The present invention is generally related to elastomeric membrane keypads and more particularly related to an improved light conducting, environmentally sealed, elastomeric membrane keypad for use in electrical devices such as portable radios.
In the prior art, elastomeric membrane keypads were typically used together with a hard plastic lightpipe for illuminating the keys thereon. The lightpipe is located between the keypad and the housing of the keypad assembly. In order to seal the keypad assembly, a two-sided adhesive pad must be placed between both the lightpipe and the keypad and between the lightpipe and the housing. Moreover, the lightpipe must be carefully designed taking into account diffraction angles of the media in order to produce adequate and even backlighting of the keys. For the foregoing reasons, there is a need for an improved elastomeric membrane keypad that eliminates the need for a separate lightpipe and the cost and problems associated therewith.